Many frozen food items intended for heating in a microwave oven are packaged in cartons or other packaging that enhance the effect of the microwave energy. However, many of such food items are packaged in a single carton that cannot be reused if the user wishes to consume less than the entire amount of food in the package. In such instances, the user must heat the entire food product, consume the desired amount, and re-heat or discard the remaining product. Unfortunately, the quality of the food item reheated in another container may be compromised.